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Talk:Combining insulin
We hope 23:15, 27 October 2006 (UTC) I've cleared cache & rebooted. Checking redirect before saving shows it's the correct redirect page. After saving, I get the proper symbol that the redirect has occurred. However, accessing this page from Main Page puts me on a non-redirected blank page. Not sure what's happening with this. Kathy If nothing works, can we agree to delete this page and start again for re-direct on it? It could be a glitch so hesitate to instantly delete it, as it may turn out to be fine later. We hope 23:20, 27 October 2006 (UTC) Don't agree, Kathy -- why? Hey Kathy -- I'm not following your logic. * Lantus does not form crystals until after it's been injected under the skin. Its pH balance is acid (unlike all other insulins which are pH balanced neutral); the crystal formation occurs when the acid Lantus meets the pH neutral skin. Changing the balance of the insulin can alter the way it performs. All agreed! Except that the 4.0 acid pH is not that of the insulin itself, is it? It's of the diluent, hence the need not to adulterate it. I don't think the insulin molecules are any more acid than your average protein. * Levemir binds to albumin found under the skin and in blood plasma34, creating an Insulin depot in the bloodstream--not subcutaneously5, as all other intermediate and long acting insulins do. Again all agreed so far, but none of this shows why it can't be combined. The molecules are quite self-contained. :Changing the insulin balance here can also result in changes in its action. I suppose it could, but where do you find this conclusion? It could also result in no changes at all, right? In summary, I still think the key to the combinability of these two insulins lies in their substrates, not their GE molecules. Diluent We hope 17:02, 17 November 2006 (UTC) Dorland's-Diluent diluent (dil·u·ent) (dil´u-ənt) 1. diluting. 2. an agent that dilutes or renders less potent or irritant. Dorland's-Solution solution (so·lu·tion) (sə-loo´shən) solutio 1. a homogeneous mixture of one or more substances (solutes) dispersed molecularly in a sufficient quantity of dissolving medium (solvent). The solute may be gas, liquid, or solid; the solvent is usually liquid, but may be solid, as in a solid solution of copper in silver (sterling silver). 2. in pharmacology, a term used to denote a liquid preparation containing one or several soluble chemical substances usually dissolved in water and not, for various reasons, falling into another category, (e.g., syrup, elixir). 3. the process of dissolving. 4. a loosening or separation. Dorland's-Excipient excipient (ex·cip·i·ent) (ek-sip´e-ənt) excipiens, from ex out + capere to take any more or less inert substance added to a prescription in order to confer a suitable consistency or form to the drug; called also vehicle. Dorland's-Vehicle vehicle (ve·hi·cle) (ve´ĭ-kəl) vehiculum excipient. structured v. an aqueous solution of a polymer used to increase the viscosity of a pharmaceutical supension and thereby decrease the sedimentation rate of the dispersed particles. sugar-free suspension structured v. NF a structured vehicle prepared from potassium sorbate, xanthan gum, citric acid, saccharin sodium, sorbitol, mannitol, glycerin, and purified water. suspension structured v. NF a structured vehicle prepared from potassium sorbate, xanthan gum, anhydrous citric acid, sucrose, and purified water. Lantus Prescribing Information LANTUS must NOT be diluted or mixed with any other insulin or solution. If LANTUS is diluted or mixed, the solution may become cloudy, and the pharmacokinetic/pharmacodynamic profile (e.g., onset of action, time to peak effect) of LANTUS and/or the mixed insulin may be altered in an unpredictable manner. This is cited in our Lantus article. Levemir Prescribing Information Mixing of Insulins If Levemir is mixed with other insulin preparations, the profile of one of both individual components may change. Mixing Levemir with insulin Aspart (Novolog/NovoRapid), a rapid-acting insulin analog, resulted in about 40% reduction in AUC (0-2h) and C (max) for insulin aspart compared to separate injections when the ratio of insulin aspart to Levemir was less than 50%. Levemir should NOT be mixed or diluted. Until such time as Sanofi-Aventis and Novo choose to do some work on this, there is no "safe" way to dilute them without risk. Diluting and combining here can change profiles--much as for the others we have listed re: not being able to combine. The act of diluting can (not written in stone) change the profile of the insulin in much the same manner as not properly mixing cloudy insulins can. Good example would be any Lente, which is 70% UL & 30% SL; not mixing them properly could result in a shot which is, let's say--35% SL and 65% UL. Change of ratio between the two and change of action, as it's based on 70% UL with 30% SL. Using it without even trying to mix the vial would mean you're giving a shot consisting of mostly solution and very little insulin-period. Much solution/little insulin for any of the cloudy types who need thorough mixing would be possible. Balance would change because you could get mainly solution with little insulin--this would certainly result in improper action. From our Rolling insulin page: An Assessment of the Adequacy of Suspension of Insulin in Pen Injectors-Diabetic Medicine (UK)-2004. The study details how NPH in pen form is affected by improper mixing before use. It can--and it can't--but until the time when someone scientifically can come up with a way to dilute/combine them which doesn't mean the outcome's questionable, it has to be "no". The solutions of these are just as important to how they perform as the alterations in the insulins themselves. Lantus, for example, given IV, has a very rapid profile. Levemir IV can do the same: Intravenous Glargine (Lantus) & Regular (Neutral) Insulin Similar Effects on Endogenous Glucose Output & Peripheral Activation/Deactivation Kinetic Profiles-ADA-Diabetes Care-2002 EMC-Electronic Medicines Compendium-UK-Levemir Levemir should not be administered intravenously as it may result in severe hypoglycaemia. Intramuscular administration should be avoided. If Levemir is mixed with other insulin preparations the profile of action of one or both individual components will change. Mixing Levemir with a rapid acting insulin analogue like insulin aspart, results in an action profile with a lower and delayed maximum effect compared to separate injections. Therefore, mixing of rapid acting insulin with Levemir should be avoided. Half of the "trick" with these is the various alterations; the other half is to delivering them in a viable solution or vehicle. Kathy